Encapsulated bleaches and methods for their preparation

ABSTRACT

Bleaching compositions containing coated or encapsulated bleaching agents, methods for employing these coated agents, as well as methods for preparing these encapsulates are disclosed. These compositions and methods are utilized to effectively bleach colored fabrics and textiles in both hot and cold water with minimal pinpoint damage to the fabric colors. The encapsulates have excellent storage properties and release of the active component at both hot and cold temperatures.

This is a Divisional of application Ser. No. 717,718, filed Aug. 25,1976 now U.S. Pat. No. 4,078,099.

The instant invention relates generally to bleaching compositionsutilized in combination with detergent compositions. The bleach is keptfrom reacting with the detergent composition, from losing its bleachingcapacity and from pinpoint damage to fabrics, where necessary, by aunique coating system which provides at least two separate coatings onthe bleaching agents or granules.

Encapsulation processes and indeed encapsulation for active chlorinebleaches as well as peroxygen bleaches is well known, see for exampleU.S. Pat. No. 3,908,045 which utilizes a non-aqueous solution ofselected fatty acids which are applied to active chlorine granules toimprove stability and to reduce the pinholing potential of the bleach.This patent, however, requires the use of a solvent system which isundesirable in certain circumstances. In addition, a number of patentsdiscussing the art of coating bleaching agents are mentioned in the U.S.Pat. No. 3,908,045. In addition to these patents, U.K. Pat. No.1,107,166 shows the difficulty of incorporating a nonionic detergentwith a chlorine bleach; SA 66/3,919 shows the encapsulation ofpercompounds with ester or amide type condensation products of fattyacids and ammonia, alkyl or alkylolamines, to deactivate chlorinecompounds in a composition. U.S. Ser. No. 359,821 filed on May 14, 1973to Gougeon now abandoned, which is the priority document of NEapplication 7,406,389, also deals with selected bleaching compositionswhich contain coated peroxy acid bleaching granules.

U.S. Pat. No. 3,112,274 discloses a method for coating and agglomeratingbleach with inorganic compounds which include the detergent components.Due to the required solubility of the coating components employed,dissolution must of necessity be too rapid to effectively controlchlorine release. Thus, while chlorine bleaching is good, pinholingdamage will be severe.

Generally, it is known that peroxygen bleaching agents are highly usefulfor chemical bleaching of colored fabrics and textiles insofar as thesebleaching agents are less harsh and more suited for colored fabrics thanconventional active chlorine type bleaching agents. The reason for thisis that many fabric dyes are susceptible to damage from chlorine bleach,although active chlorine type bleaching agents are preferable becausethey are stronger and do a much better job of bleaching. These activechlorine containing compounds are generally utilized in solid orgranular form if they are to be mixed in with a particulate detergentcomposition.

Granular products containing chlorine bleaching agents frequently resultin fabric color damage. These products are generally added to a dry loadof laundry in a conventional washing machine and remain in close contactwith fabrics during the time that the conventional washing machines arebeing filled with water. As the machine fills, local high concentrationsor even pastes of the compounds come into contact with the fabricsurfaces. When this happens the bleaching conditions on the fabricsurface are extremely favorable for color damage and very small spots orpinpoints will appear on the fabric surfaces. These conditions result indamage to the fabric color in a pinpoint pattern.

Pinpoint color damage can be minimized by employing various methods todelay solubility of the bleaching material until after the washing tubhas completely filled and agitation has begun. This avoids local areasof high bleach concentration. One method of achieving this delay hasbeen to coat or encapsulate the bleaching granules thereby preventingimmediate contact with the wash water. These coatings and the proceduresemployed have inherent shortcomings. A coating material must be employedwhich adequately serves to provide the delay indicated above. At thesame time, the coating must be of such a nature that it will allowsubstantially complete release of the bleach into solution during thewash cycle. Thus, it is apparent that two seemingly contradictoryresults are sought. In addition, the coating material must be of such anature as not to substantially interfere with the washing process. Forexample, the material must be such as not to increase soil levels in thewash. Further, an appropriate coating material must aid in stabilizationof the chemically reactive bleaching agents during prolonged periods ofstorage either alone or in admixture with various detergent products.Also, the coating must not react with either the bleaching agent or withthe other components of the composition such as detergents or builders.In addition, in order to formulate a practical bleach containingdetergent, the composition must not only bleach at high temperatures,such as for example about 135° F., but must also bleach at warmtemperatures such as about 100° F. and cold temperatures such as about75° F. These requirements present an extremely difficult problem inobtaining a bleaching composition which will not pinhole yet willrelease high effective levels of chlorine at both high and lowtemperatures. Prior art solutions to the problem have not beencompletely satisfactory since the coating agents are highly temperaturedependent. Thus, when hot water enters the washer, it will immediatelymelt a coating compound which has a melting point lower than thetemperature of the wash water. On the other hand, if the coatingmaterial melts at a high temperature and if low wash water temperaturesare used, only a small amount of bleach will be released in the washwater. This is a problem if it is desired to release chlorine at lowertemperatures for its bleaching and antiseptic properties. It can thus beseen that a method of coating active chlorine bleach granules and aproduct of good stability prepared by this method which would releasehigh effective amounts of chlorine at both high and low temperatures andwhich would minimize pinholing on colored fabrics is extremelydesirable.

While the problem of pinholing is not serious with oxygen containingbleaching agents, the problem of low and high wash water temperaturerelease coupled with storage stability still exists. Thus a coatingsystem which will substantially diminate these problems is alsodesirable.

It is therefore an object of the invention to provide a method forpreparing encapsulated bleach granules which will not be subject to oneor more of the above disadvantages.

Another object is to provide an improved method for preparingencapsulated chlorine granules having a delayed release providing higheffective levels of chlorine at both high and low temperatures, andminimal fabric color damage.

Yet another object is to provide a coating for chlorine granules as wellas other agents for which controlled release is necessary or required.

A further object is to provide a practical and efficient method ofpreparing chlorine granules which are stable over a reasonably longperiod of time and which can be utilized with a granulated detergentcomposition.

Other objects and advantages will appear as the description proceeds.

The attainment of the above objects is made possible by this inventionwhich includes an encapsulating composition, encapsulated activechlorine bleach granules as well as other granules and methods forpreparing the same.

The subject invention overcomes one or more of the disadvantages of theprior art heretofore described. This is accomplished with the advantagesthat such encapsulation may be more easily achieved; uses moreeconomical and safer starting materials; and will enable inclusion of ableach granule into a commercially practical detergent composition. Anadditional advantage is its utility in either high or low temperaturewash water with no substantial fabric color damage or pinholing.

With these and other objects in mind, the invention is hereinafter setforth in detail, the novel features thereof being particularly pointedout in the appended claims.

Generally, in the practice of the present invention, the method isperformed substantially as follows: the granulated material to beencapsulated is charged into a rotating drum mixer, molten, solvent freecombinations of selected fatty acids and waxes are sprayed onto thetumbling granules by means of a two fluid nozzle which is fullydescribed in Alterman, U.S. Pat. No. 3,908,045 which description ishereby incorporated by reference. The molten combination is sprayed in afinely divided state and at a rate which prevents excess agglomerationand results in the application of a coating of the combination on theparticles. Materials containing a small amount of fines, up to about 20%and preferably no more than 10%, are agglomerated in situ with some ofthe coating agent initially sprayed. This initial step, prior to thestart of the actual encapsulation, eliminates the need of most prior artprocesses to pre-screen the material to be encapsulated. The granulatedmaterial utilized herein is substantially passed through a U.S. sievesize of about 10 mesh and substantially retained on a U.S. sieve size ofabout 45 mesh. Fines as used herein may be defined as particles whichpass through a U.S. sieve size of about 45 mesh. The internal airtemperature of the mixer is critically maintained within the softeningrange of the coating combination or agent to obtain a coherent coating.Processes not maintaining such temperature control result in lesscoherent coatings. Without the temperature control a significant portionof the atomized coatings will have solidified prior to contacting thegranules. This spray drying effect results in a significant portion ofthe coating material having no adhesion to the granules.

More specifically, sufficient chlorinating agents are placed in the drummixer (pre-screening of the fines is unnecessary). The coating agentsare placed in a pot with a steam coil and melted together. All coatingmaterials used are preferably entirely miscible when melted. No organicor inorganic liquids other than the melted coating agents are used. Theprocess is thus solventless in the sense that only the coating materialsare used. The bulk of the coating material is a non-reactive fatty acidin combination with a microcrystalline wax. It has been found that themelting points of these materials are preferably fairly well-matched.

After melting the coating agents, in the absence of solvents, theseparate premixes are prepared. With the mixer rotating and thechlorinating agent tumbling, the coating agent is applied by spray viathe two fluid nozzle, previously described, with the use of a pressurepot. This produces a finely atomized spray of coating aspect which isdirected at the center of the tumbling powder. The rate of applicationmust be sufficient so as to avoid agglomeration which results fromlocalized overwetting. Such a low rate of application results in thebuilding of layer on layer of coating on the particles. The waxes assistin this process by acting as "lubricants" in the application of thelayers of coating.

During the application of the coating, it has been found extremelyimportant to maintain an ambient air temperature in the mixer within thesoftening range of the coating agent to allow the coating to spreadaround the particle. This is accomplished in any convenient manner, forexample, with the use of a simple electric hot air blower. Maintainingthis temperature prevents the molten liquid from solidifying too quicklyand affords a more coherent coating. By elevating the temperature nearthe melting point of the coating during the initial stages of theprocess, agglomeration will occur thereby eliminating any fines presentin the powder. When formulas contain multiple coatings, these are simplysprayed back-to-back in sequence.

After spraying all the coating material, the hot air flow into the mixeris shut off and the encapsulated particles are permitted to coolnaturally. While this is occurring, if desired, the hot air blowers aredirected to the outside shell of the mixer for a sufficient amount oftime to heat the metal shell to a temperature at least into thesoftening range of the coating. Generally in burnishing the particles,heat will be applied to the shell of the mixer for 3-10 minutes,preferably about 5-7 minutes in the softening range of 130°-140° F. Asthe coated particles roll along the interior wall of the mixer, aburnishing effect takes place. As the particles lose contact with themixer wall the surface temperature of the particles quickly drop and thecoating hardens again. This cycle is repeated until the particles can beseen to have acquired a gloss. This indicates the "burnishing" step iscomplete and the coherency of the coating has been measurably improved.This encapsulated material is now ready for blending into a detergentpowder. Tailings (particles greater than 10 mesh) are generally found tobe less than 1%, indicating that screening can be avoided, if desired.

Coating agents with inverse solubility in water may be incorporated intothe coating combination described above as either a first or secondcoat. This inversely soluble material provides for a high effectiverelease of the encapsulate in both hot and cold water, depending on thereactivity of the granulated material or encapsulate. As a final stepafter spraying the coating agents, the coated particles are preferablyburnished by the application of heat on the outer shell of the drummixer which softens and reforms the outer surface of the coating andimproves its coherency. Although this burnishing step is not required,it provides for a more coherent coating and thus greater effectivenessof the coating. It will be apparent that by increasing the amount ofcoating employed an equivalent effect can be achieved. The use of anexcess of coating material, however, is more costly and is thus notdesirable.

When employing an active chlorine bleach, the coating of the inventioninvolves a first non-reactive coat which separates the active chlorinecontaining compound from the second or time control coat. A second ortime control coat, including the material having inverse solubility, isthen applied over the protective or first coat. In this way materialswhich may react with the encapsulate can be utilized. Heretoforeinclusion of certain desirable out reactive materials could not beachieved. In addition to the second or time control coat, a thirdcoating can be used to further improved the coherency of the coating,and to increase the amount of time necessary for the coating to releasethe active chlorine containing agents. The first coating is acombination of a fatty acid and preferably a microcrystalline wax. Thesecond coating is a combination of a fatty acid with material whichexhibits inverse solubility with respect to temperature. This providesfor a greater release of the encapsulate in cold water than in hotwater. By this means sufficient delayed release is provided in hot waterto prevent pinholing. These materials may be for example pluronicsurfactants (a trademark of Wyandotte Chemical Co.) i.e. a condensationproduct of polyoxypropylene and polyoxyethylene. In addition to this, awax can be used in the second coating. The third coating, if desired,can be a fatty acid in combination with a wax.

If a compound is used as the encapsulate which is substantiallynon-reactive as compared to chlorinating agents, then the first,protective coat can be eliminated and the second or time release coatcan be utilized directly covering the encapsulate. If in addition colordamage is of no concern, then a material which is simply soluble inwater and miscible with the other coating components can be substitutedfor the materials possessing inverse solubility. This still provides asignificant benefit in that release of the encapsulate is substantiallytemperature independent since the water soluble material is leached fromthe coating causing coating breakdown followed by release of theencapsulate. Substantially non-reactive materials which will benefitfrom the encapsulation are oxygen-releasing bleaches, such as forexample, sodium percarbonate, sodium perborate as well as reducingbleaches such as sodium bisulfite. In addition, other materials whichcan benefit from controlled release may also be utilized.

The final product then can be an oxidizing or reducing bleach as well asthe preferred active chlorine containing bleaching agent encapsulatedwith the aforedescribed coatings.

When a dual coating is to be applied, it is essential that the firstcoating contain a major portion of a saturated fatty (alkanoic) acidwhich is solidifiable and which remains solid at temperatures likely tobe encountered during storage and subsequent manufacturing steps such asinclusion into a detergent composition, for example a temperature ofabout 85°-135° F.

Suitable fatty acids are the well known n-alkanoic acids having fromabout 12 to about 20 carbon atoms. The critical feature of the fattyacid is its melting point to insure that the coating is substantiallyindependent of wash water temperature. Thus, any combination of thesefatty acids which has the required melting point may be used. Smallamounts of unsaturated acids are tolerable so long as there issubstantially no reaction of the total mixture with the encapsulatedmaterial. Various combinations of the acids may thus be utilized.Particularly suitable fatty acids are for example Emersol 150 andEmersol 153 (trademarks of Emery Industries, Inc.). Emersol 150 isessentially a combination of 83% stearic acid, 11% palmitic acid and 6%of other fatty acids, Emersol 153 is essentially a combination of 95%stearic and 5% palmitic acids.

The waxes of the invention are utilized in essence as a plasticizer toimprove the flow of the coating around the particles and to improve thecoating coherency by reducing the crispness and brittleness of the fattyacid used alone. These waxes may be any substantially saturatednon-reactive blend of normal paraffins, isoparaffins, and alkylatednaphthenes (cycloparaffins). Preferably microcrystalline waxes having amelting point range of about 125° to 210° F., as measured by the ASTMD-127 melting point test, are employed. These waxes typically have amolecular weight of about 500 to about 750 and a hardness value of about2 to about 80 as defined by the ASTM needle penetration test at 77° F.(ASTM D-1321).

Particularly preferred are microcrystalline waxes marketed by WitcoChemical Company under the trademark "Multiwax", such as for exampleMultiwax X 145A having a melting point of about 160° to 170° F. The waxand the fatty acid used should have softening and melting points whichare approximately in the same range, for example Multiwax 110 with a C₁₂fatty acid and Multiwax HS with Emersol 153. The amount of wax utilizedis sufficient to substantially overcome the brittleness of the fattyacid without making the coating too sticky which will occur if too muchwax is used. Generally, about 2% to 18% is included and preferably about5% to about 15% to insure proper plasticity of the coating without unduestickiness.

The material used to provide a temperature independent release of theencapsulate is used in either the first or second coating depending uponthe reactivity of the encapsulate. For chlorine releasing bleachgranules, this material will be included in the second coat. Thepreferred material being a pluronic surfactant is marketed byBASF-Wyandotte Chemical Company.

The pluronic surfactants that may be utilized are fully described inU.S. Pat. No. 2,979,528. The pluronics which may be employed have anaverage molecular weight of about 8000 to about 16,500. The pluronicsare solids and the percent of polyoxyethylene in the molecule is about65% or greater. The melting point of the mixture of the coatingcontaining the pluronic must melt at close to or above the wash watertemperature to be utilized. In addition, PLURAFAC A-38, also marketed byWyandotte Chemical Company, may also be operable.

These pluronic surfactants are preferred because of their inversetemperature solubility in water, i.e. they are less soluble in hot waterthan in cold water. For encapsulates which pose only a minimum pinholingproblem the delay release requirements are less stringent and thereforematerials exhibiting normal solubility such as Carbowax 6000, a productmarketed by Union Carbide Corporation, will suffice. The Carbowax is apolyethylene glycol polymer having a molecular weight of about 6000.

Generally, the total coating will be 45 to 55% by weight of the totalparticle. The minimum that can be used is about 35%. The maximum, ofcourse, is not critical except that the coating will be too costly if anexcess is used. The amounts of the various layers considered as apercentage by weight of the total encapsulated particle are as follows:

A. Three Coat System

(1) layer one, about 5-15%, preferably about 8-12%: the components oflayer one are present in the layer in the following amounts:

fatty acid--about 82% to about 98% by weight of layer one, preferablyabout 85% to 95% by weight;

microcrystalline wax--about 2% to about 18% by weight of layer one,preferably about 5% to about 15% by weight;

(2) layer two, about 25-40%, and preferably about 30-35%: the componentsof layer two are present in the layer in the following amounts:

fatty acid--about 16% to about 86% by weight of layer two, preferablyabout 45% to about 76% by weight;

microcrystalline wax--about 0.5% to about 16% by weight of layer two,preferably about 3% to about 12% by weight;

inverse solubility material--about 12% to about 80% by weight of layertwo, preferably about 20% to about 47% by weight.

(3) layer three, about 5-15%, and preferably about 8-12%. The componentsof layer three are present in the layer in the same relative amounts asin layer one above.

In layer two, the amount of the material having inverse solubility isabout 5-20%, and preferably about 7-14% of the total encapsulate weight.

B. Two Coat System

(1) layer one, about 15-25%, preferably about 18-20%. The components oflayer one are present in the layer in the same relative amounts as inlayer one of the three coat system above.

(2) layer two, about 30-40%, preferably about 32-38%: the components oflayer two are present in the layer in the following amounts:

fatty acid--about 27% to about 86% by weight of layer two, preferablyabout 48% to about 78% by weight;

microcrystalline wax--about 0.5% to about 16% by weight of layer two,preferably about 3% to about 12% by weight;

inverse solubility material--about 12% to about 67% by weight of layertwo, preferably about 18% to about 44% by weight.

In layer two, the amount of inverse solubility material is about 5-20%,preferably about 7-14% of the total encapsulate weight.

C. One Coat System

(1) layer one, about 35-55%, preferably about 45-50%. This layer hasabout 5-20%, and preferably about 7-14% of the total encapsulate weightof the material exhibiting inverse solubility: The components of thislayer are present in the layer in the following amounts:

fatty acid--about 35% to about 89% by weight, preferably about 59% toabout 82% by weight;

microcrystalline wax--about 1% to about 16% by weight, preferably about3% to about 13% by weight;

inverse solubility material about 9% to about 57% by weight, preferablyabout 14% to about 31% by weight.

Among the chlorine-releasing or active-chlorine containing substancessuitable as encapsulates, there may be mentioned those oxidants capableof having their chlorine liberated in the form of free elementalchlorine under conditions normally used for detergent bleachingpurposes, such as potassium dichloroisocyanurate, sodiumdichloroisocyanurate, chlorinated trisodium phosphate, calciumhypochlorite, lithium hypochlorite, monochloramine, dichloramine,nitrogen trichloride [(mono-trichloro)-tetra-(mono-potassiumdichloro)]penta-isocyanurate, 1,3-dichloro-5,5-dimethyl hydantoin,paratoluene sulfondichloroamide, trichloromelamine, N-chloromelamine,N-chlorosuccinimide, N,N'-dichloroazodicarbonamide, N-chloro acetylurea, N,N'-dichlorobiuret, chlorinated dicyandiamide, trichlorocyanuricacid, and dichloroglycoluril.

Sodium dichloroisocyanurate, typical of the cyanurates suitable as coresubstances, is commercially available and may be obtained from theMonsanto Chemical Company. The chemical structure of this compound maybe represented by the formula ##STR1## Information regarding this andrelated compounds may be found in Monsanto Technical Bulletin 1-177.Potassium dichloroisocyanurate, while not preferred, may also beemployed.

Additional chlorinated compounds of the type referred to in the instantspecification as chlorine-releasing agents, which liberate elementalchlorine under the conditions of use set forth herein, are well known inthe detergent, bleaching and sanitizing arts. Disclosures of typicalchlorine-releasing agents, preparative procedures, and use incombination with certain detergents and additives may be foundcollectively in the following list of patents, which is by no meansexhaustive.

U.S. Pat. No. 1,555,474

U.S. Pat. No. 1,950,956

U.S. Pat. No. 1,965,304

U.S. Pat. No. 2,929,816

U.S. Pat. No. 3,035,054

U.S. Pat. No. 3,035,056

U.S. Pat. No. 3,035,057

U.S. Pat. No. 3,110,677

U.S. Pat. No. 3,346,502

Suitable chlorine-releasing agents are also disclosed in the ACSMonogram entitled "Chlorine--Its Manufacture, Properties and Uses" bySconce, published by Reinhold in 1962.

When utilizing the encapsulated particles of this invention in adetergent formulation the desired chlorine level in the wash solution isabout 30 to about 200 parts per million (ppm) available chlorine. Thepreferred range is about 15 to about 35 ppm to most efficiently utilizethe chlorine containing material. These levels determine the amount ofencapsulated particles which are incorporated into the detergentformulation.

Encapsulated particles of chlorine-releasing agent prepared inaccordance with the instant specification find utility in admixture withparticulate detergent compositions having therein anionic and/ornonionic detergent species.

Examples of anionic detergents useful in the detergent-bleachcompositions of this invention are the higher alkyl mononuclear aromaticalkali-metal sulfonates, such as alkylbenzenesulfonates having about 9to 18 carbon atoms in the alkyl group wherein the alkyl group is derivedfrom polypropylene as described by Lewis in U.S. Pat. No. 2,477,382, orwherein the alkyl group is derived from kerosene, as described by Flettin U.S. Pat. No. 2,390,295, and Rubinfeld in U.S. Pat. No. 3,320,174, orwherein the alkyl group is a straight chain and the benzene nucleus israndomly positioned along the alkyl chain, as described in BaumgartnerU.S. Pat. Nos. 2,723,240 and 2,712,530 and in U.S. Pat. No. 2,972,583,or wherein the alkyl group is a hexene dimer or trimer as in McEwan U.S.Pat. No. 3,370,100, or wherein the alkyl group is derived fromalphaolefins, as in Swenson U.S. Pat. No. 3,214,462.

Also there may be employed primary and secondary alkyl sulfates, i.e.R-O-SO₃ -- compounds wherein R represents an alkyl group having from 10to 20 carbon atoms such as sodium, potassium and magnesium laurylsulfate, stearyl sulfate, coconut alkyl sulfate and tallow alkylsulfate; N-long chain acyl-N-alkyl taurates and the salts thereofwherein the long chain is from 8 to 20 carbon atoms such as sodiumoleoyl methyl taurate, sodium palmitoyl methyl taurate, sodium lauroylmethyl taurate and the corresponding acyl ethyl taurates; long chainalkyl-oxyethylene sulfonates wherein the long chain is from 8 to 20carbon atoms such as sodium or laurylpolyoxyethylene sulfate, sodiumlauryloxyethylene sulfate and sodium cetylpolyoxyethylene sulfate; longchain alkyl aryl oxyethylene sulfates wherein the long chain is from 8to 20 carbon atoms such as ammonium, sodium or potassium nonyl- octyl-and tridecylphenoxy mono- and polyoxyethylene sulfates; long chainacylisethionates wherein the long chain is from 8 to 20 carbon atomssuch as sodium or potassium lauroyl- stearoyl isethionate; alkane- oralkenesulfonates containing 8 to 20 carbon atoms in the alkane or alkenegroup such as sodium or potassium octane-, decane-, tetradecane-,octadecanesulfonate and octene-, decene-, tetradecene- andoctadecenesulfonate; alkoxyhydroxy- alkanesulfonates wherein the longchain is 8 to 22 carbon atoms such as lauryloxyhydroxypropanesulfonate,stearyloxyhydroxyethanesulfonate and tallowoxyhydroxypropanesulfonate;and fatty acid monoglyceride sulfates wherein the long chain is 8 to 22carbon atoms such as lauric-, myristic-, palmitic and stearicmonoglyceride sulfates; alpha-sulfo soap, such as disodium salt ofalpha-sulfo fatty acids wherein the fatty acids are derived from tallow,the sulfosuccinates, such as dioctyl sulfosuccinate, sodium salt, thesulfuric acid esters of polyhydric alcohols incompletely esterified withhigher fatty acids, such as the sodium salt of sulfated coconut oilmonoglyceride, and compounds known as "Medialans", which are amidocarboxylic acids formed by condensing fatty acids of C₈ -C₂₂ chainlength with sarcosine, CH₃ NH₂ CH₂ COOH. Generally the alkali metalsalts are employed.

The soaps are included within the definition of anionic detergents asused herein. Operable soaps within the present invention are the sodiumand potassium salts of acyclic monocarboxylic acids having chain lengthsof about 8 to about 22 carbon atoms. Particularly useful are the saltsof unsubstituted fatty acids derived from natural triglycerides, such astallow, palm oil, cottonseed oil, olive oil, lard, rapeseed oil, etc.,and the so-called "high-lauric oils," generally exemplified by thetropical nut oils of the coconut oil class, including in addition tococonut oil, palm kernel oil, babassu oil, ouri curi oil, tucum oil,cohune nut oil, and murumuru oil, and for present purposes, ucuhubabutter, a triglyceride high in myristic acid esters. A particularlyuseful soap is one prepared from a mixture of about 80% tallow and about20% coconut oil.

Preferably the detergent composition should be substantially free ofcompounds containing amino nitrogen to avoid adverse effects during thewashing operation.

Other suitable anionic synthetic detergents for use in the presentinvention can be found in the literature, such as "Surface Active Agentsand Detergents" by Schwartz, Perry and Berch published by IntersciencePublishers, the disclosures of which are incorporated by referenceherein.

Water-soluble polyetheneoxy nonionic organic detergent compoundssuitable for use in the practice of the invention may be characterizedbroadly as ethylene oxide condensates of organic hydrophobic compoundsbearing a labile hydrogen atom in a polar substitutent, said organichydrophobic compounds being within a molecular weight range such thatwhen serving as a base for a resulting ethylene oxide condensate, saidcondensate is capable of having detergent properties at a sufficientlyhigh ethylene oxide content.

Suitable hydrophobic bases falling within the foregoing description arealiphatic alcohols and mixtures thereof having from about 10 to about 15carbon atoms, corresponding to an average molecular weight of about 158to about 228. The alcohol is preferably straight-chain, but may contain0% to about 25% lower alkyl branching, mainly methyl, with some 2-3carbon alkyl groups, on the 2-position carbon of the alcohol molecule.

Other suitable hydrophobic compounds include:

(a) the polyoxypropylene diols which form the hydrophobic base of thePluronics. "Pluronic" is a trademark of the Wyandotte Chemical Corp. Theaforementioned hydrophobic base is water-soluble and has a molecualrweight from about 1500 to about 1800.

(b) Alkylphenols having an alkyl group of about 6 to about 12 carbonatoms. The alkyl group may be straight or branched and may be derivedfrom a propylene polymer, diisobutylene, hexene, nonene, or dodecene,for example, or mixtures of these.

The ethylene oxide content of the detergent molecule may range from 52%to about 80% by weight, preferably from about 60% to about 70% byweight.

Among the water-soluble polyetheneoxy organic nonionic detergentcompounds useful in the combinations of the instant invention are

(1) condensates of ethylene oxide and a primary or secondary alkanolhaving about 8 to about 16 carbon atoms, the proportion of combinedethylene oxide being from about 52% to about 80% by weight, and mixturesthereof.

(2) condensates of ethylene oxide and an alkanol having 14-15 carbonatoms with about 25% 2-methyl branching, the proportion of combinedethylene oxide in said condensate being from about 52% to about 80% byweight, and mixtures thereof.

(3) condensates of ethylene oxide and a hydrophobic base selected fromthe group consisting of the reaction product of propylene oxide andpropylene glycol, said reaction product having a molecular weight ofabout 1800.

The water-soluble polyetheneoxy organic nonionic detergent compounds mayinclude:

(1) Poly (ethylene oxide) condensates of primary or secondary aliphaticalcohols having about 11 to about 15 carbon atoms, said condensateshaving an average of about 9 molar proportions of ethylene oxide permole of alcohol, and mixtures thereof.

(2) Poly (ethylene oxide) condensates of primary aliphatic alcoholshaving about 12 to about 15 carbon atoms and having about 25% loweralkyl branching on the 2-carbon, said condensates having an average ofabout 9 to about 20 molar proportions of ethylene oxide per mole ofalcohol, and mixtures thereof.

(3) A condensate of 1 mole of octylphenol and about 7-8 molarproportions of ethylene oxide.

(4) Poly (ethylene oxide) condensates of linear primary alcohols havingabout 14-15 carbon atoms, and averaging about 13.5 carbon atoms, andhaving about 25% lower alkyl branching on the 2-carbons, saidcondensates having an average of about 13.5 molar proportions ofethylene oxide per mole of alcohol.

(5) The poly (ethylene oxide) condensates of alkylphenols, e.g., thecondensation of products of alkylphenols having an alkyl groupcontaining from about 6 to 12 carbon atoms in either a straight chain orbranched chain configuration, with ethylene oxide, said ethylene oxidebeing present in amounts equal to 6 to 25 moles of ethylene oxide permole of alkylphenol. The alkyl substitutent in such compounds may bederived from polymerized propylene, diisobutylene, octene, dodecene, ornonene, for example.

(6) Compounds formed by the simultaneous polymerization of propyleneoxide and ethylene oxide, and containing randomly postioned propeneoxyand etheneoxy groups.

As examples of specific nonionic detergent compounds finding utility inaccordance with the invention, there may be mentioned:

(A) branched-chain nonyl phenol condensed with about 8-14 molarproportions of ethylene oxide,

(B) a mixed C₁₁ -C₁₅ secondary alcohol condensed with 9-14 molarproportions of ethylene oxide, the mixed secondary alcohols having thefollowing approximate chain-length distribution:

2% C₁₀

15% C₁₁

21% C₁₂

23% C₁₃

17% C₁₄

15% C₁₅

7% C₁₆,

(C) a mixed C₁₄ -C₁₅ alcohol made by the Oxo process condensed withabout 9-15 molar proportions of ethylene oxide, and

(D) a mixture of about 65% C₁₄ and about 35% C₁₅ syntheticstraight-chain primary alcohols condensed with about 9-15 molarproportions of ethylene oxide.

The compositions of the present invention may be formulated with adetergent builder as a detergency aid, for example, those mentionedhereinafter, to provide a commercially valuable detergent-bleachcomposition.

The term "builder" as used herein refers to any substance compatiblewith, and assisting the detergency of the aforementioned combination.

Suitable builder compositions are tetrasodium and tetrapotassiumpyrophosphate, pentasodium and pentapotassium tripolyphosphate,carboxymethyloxysuccinate, substituted carboxymethyloxysuccinates andthe like, sodium or potassium carbonate, sodium or potassium silicateshaving an SiO₂ :Na₂ O ratio of about 1:1 to about 3.2:1, hydrated oranhydrous borax, sodium or potassium sesquicarbonate, phytates,polyphosphonates such as sodium or potassiumethane-1-hydroxy-1,1-diphosphonate, etc.

Also useful are other organic detergent builders such as the sodium orpotassium oxydisuccinates, sodium or potassium oxydiacetates, hydrofurantetracarboxylates, ester-linked carboxylate derivatives ofpolysaccharides, such as the sodium and potassium starch maleates,cellulose phthalates, semi-cellulose diglycolates, starch, oxidizedheteropolymeric polysaccharides, etc. The weight percent of the builderpresent in the built anionic detergent composition is from an amount ofabout 6% and up to about 90% and preferably from about 20% to about 60%.Suitably, a builder may be present in the ratios of about 0.5 to about10 parts by weight, preferably about 2 to about 5 parts by weight, foreach part by weight of the detergent component.

Other materials which may be present in the detergent compositions ofthe invention are those conventionally employed therein. Typicalexamples include the well-known soil suspending agents, corrosioninhibitors, dyes, perfumes, fillers, optical brighteners, enzymes,germicides, anti-tarnishing agents, and the like. The balance of thedetergent composition may be water.

The detergent compositions with which the encapsulated bleaching agentsof the invention find utility may have compositions represented by thefollowing components and ranges of proportions thereof:

    ______________________________________                                                            APPROXIMATE                                                                   PERCENTAGE                                                ______________________________________                                        Anionic or nonionic detergent                                                                         1- 90%                                                Builder                 0- 90%                                                Encapsulated bleaching agent                                                                          2- 25%                                                Optical brightener      0- 0.3%                                               Viscosity enhancer      0- 1%                                                 Water                   5- 15%                                                Sodium sulfate          0- 25%                                                ______________________________________                                    

Detergent compositions formulated for use in the washing of fabrics inautomatic washing machines may contain about 5% to about 30% anionicdetergent, about 30% to about 60% of one or more of the buildersmentioned hereinabove, and sufficient encapsulated bleaching agent toprovide 30-200 parts per million chlorine in the wash water, orapproximately 2% to 25% of the agent in the detergent formution. Usuallyincluded are about 0.1-0.3% optical brightener, and about 0.4% sodiumcarboxymethylcellulose or other material as a viscosity enhancingmaterial and if desired, small proportions of other components such asgermicides, anti-caking agents, etc. to confer special properties on theproduct.

When the detergent is soap, and comprises the major proportion of thedetergent-bleach product, the soap may be present in amounts from about60% to about 90%, little or no builder being required, although about 1%to about 10% of an alkaline builder may be advantageous.

When the detergent is nonionic, from about 5% to about 20% is suitable,the balance of the composition being as listed above.

Detergent compositions formulated for mechanical dishwashers and havingthe encapsulated bleaching agents of the invention therein may containlow proportions of nonionic detergent, for example about 1% to about 4%,and may contain a suds depressant and a high proportion of a builder,for example about 50-90% of a mixture of sodium tripolyphosphate, sodiumcarbonate, and sodium silicate.

Pinholing test data and chlorine release test data are obtained in thefollowing manner:

PINHOLE EVALUATION TEST

This test is carried out in a washing machine (standard wash and rinsecycles) using 1 cup of detergent formulation plus sufficient encapsulantcalculated to give 30 ppm available chlorine in wash.

Four pieces of blue denim (10"×10") are placed on top of a six poundload (pillow cases). The powder containing the encapsulant is poured ontop of the blue denim to provide the maximum opportunity for fabricdamage to the blue denim. The fill up time is ˜2-3 minutes. Accordingly,delayed release of up to 5 minutes is needed to avoid damage to thefabric.

Damage to the blue denim swatches is assessed visually according to thescale

0--no pinholing

1--slight pinholing

2--medium pinholing

3--heavy pinholing An acceptable rating is 0 to 1.

After a normal wash rinse cycle the fabric is removed from the machine,dried and evaluated.

CHLORINE RELEASE TEST

This test is conducted with "standard" wash water temperatures of 135°F., 100° F., and 75° F. (hot, warm, cold). A six-pound "dummy" load ofwhite articles is placed in the machine first. The machine is allowed tofill with water during which time the hot and cold water inlets areadjusted to provide the desired water temperature. With the machine inoperation a known quantity of encapsulate together with a normalquantity (1 cup) of a detergent powder is placed in the wash water. If acomplete chlorine release profile is desired, then wash water samplesare removed after 2, 5, 8, 10 and 12 minutes. These samples are weighedand a standard chlorine analysis by thiosulfate titration is conducted.A comparison of the actual chlorine content of the samples with thetheoretical level of available chlorine for release determines thepercent chlorine release (usually reported for the 12-minute period).

The results of tests run are reported in individual examples.

The following Examples will more fully illustrate the embodiments ofthis invention. All parts and proportions referred to herein and in theappended claims are by weight unless otherwise indicated.

EXAMPLE 1

Encapsulated bleach is prepared having the following composition:

    ______________________________________                                                                Percent                                               ______________________________________                                        sodium dichloroisocyanurate dihydrate                                                                   47.0                                                (a) Emersol 150                   7.5                                                              Coat 1                                                   (b) Witco X-145A wax              0.83                                        Emersol 150                       22.17                                       Witco X-145A wax     Coat 2       2.5                                         (c) Pluronic F-127                10.0                                        Emersol 150                       9.0                                                              Coat 3                                                   Witco X-145A wax                  1.0                                                                           100.0                                       ______________________________________                                         (a) 83% stearic acid                                                           11% palmitic acid                                                              2% myristic acid                                                              2% margaric acid                                                              1% pentadecanoic acid                                                         1% oleic acid                                                               (b) a microcrystalline wax containing a blend of alkylated naphthenes,        isoparaffins and normal paraffins having a melting point of about             145° F. to 155° F.                                              (c) a block copolymer of 80% polyoxyethylene and 20% polyoxypropylene wit     an approximate molecular weight of 13,330.                               

The first step in preparing a batch of the encapsulated material is toload the batch weight of the sodium dichloroisocyanurate dihydrate intothe mixer. The hot air blower is started and the air temperature in themixer is slowly raised to about 135° F., at which point a portion ofCoat 1 is added by a two fluid spray nozzle. With the temperature at ornear the melting point of Coat 1, agglomeration of any fines present inthe chlorocyanurate occurs. With the air temperature in the mixerlowered below the melting point of Coat 1, the remaining portion of Coat1 is sprayed. This first coating is also intended to act as a barrier toseparate the chlorocyanurate from the Pluronic F-127 in the second coat.

Following addition of Coat 1, the air temperature in the mixer islowered to 105° F.-110° F. and Coat 2 is sprayed, followed by Coat 3.After spraying Coat 3, the internal air temperature of the mixer isallowed to drop and heat is applied to the outer shell of the mixer toburnish the particles and improve the coherency of the coating.

A. % CHLORINE RELEASE IN WASH WATER AFTER 12 MINUTES AT TEMPERATUREINDICATED

    ______________________________________                                        Wash Water Temperature                                                        °F.        % Chlorine Release                                          ______________________________________                                        135               100.0                                                       100               87.8                                                        75                75.0                                                        ______________________________________                                    

B. Pinhole Rating After Pinhole Test=0 to 1

The compositions of Examples 2 through 17 inclusive are prepared inexactly the same manner as Example 1 except the number of coats isvaried.

EXAMPLE 2

    ______________________________________                                                                Percent                                               ______________________________________                                        sodium dichloroisocyanurate dihydrate                                                                   47.00                                               (a) Emersol 150                   16.50                                                           Coat 1                                                    (b) Witco X-145A                  1.83                                        Emersol 150                       22.17                                       Witco X-145A        Coat 2        2.50                                        (c) Pluronic F-127                10.00                                                                         100.00                                      ______________________________________                                         (a), (b), (c) as defined under Example 1.                                

A. % CHLORINE RELEASE IN WASH WATER AFTER 12 MINUTES AT TEMPERATUREINDICATED

    ______________________________________                                        Wash Water Temperature                                                        °F.        % Chlorine Release                                          ______________________________________                                        135               74                                                          100               91                                                          75                95                                                          ______________________________________                                    

B. Pinhole Rating After Pinhole Test=1

EXAMPLE 3

    ______________________________________                                                                Percent                                               ______________________________________                                        sodium dichloroisocyanurate                                                                             47.00                                               (a) Emersol 150                   7.50                                                            Coat 1                                                    (b) Witco X-145A                  0.83                                        Emersol 150                       22.17                                       Witco X-145A        Coat 2        2.50                                        (c) Pluronic F-127                10.00                                       Emersol 150                       9.00                                                            Coat 3                                                    Witco X-145A                      1.00                                                                          100.00                                      ______________________________________                                         (a), (b), (c) as defined under Example 1.                                

A. % CHLORINE RELEASE IN WASH WATER AFTER 12 MINUTES AT TEMPERATUREINDICATED

    ______________________________________                                        Wash Water Temperature                                                        °F.        % Chlorine Release                                          ______________________________________                                        135               85.0                                                        100               100.0                                                       75                75.0                                                        ______________________________________                                    

B. Pinhole Rating After Pinhole Test=0 to 1.

C. STORAGE TESTS FOR EXAMPLE 3 UNDER TWO DIFFERENT CONDITIONS ARETYPICAL FOR ENCAPSULATED PRODUCTS

1. In a high humidity test at 80° F./80% relative humidity, whereincommon package boxes become saturated, the encapsulate of Example 3 (10%level) was stored for a 3-month period in aluminum foil wrapped boxes.At the same time a mixture of the unencapsulated chlorocyanurate withRinso was similarly stored as a control. These boxes containing 100 gramsamples were analyzed after 1, 2, and 3 months for chlorine content. Inanalyzing these samples the contents of the box is divided into 3samples and titrated in a normal chlorine test. The chlorine dataobtained is compared to the initial chlorine content and a percent lossis determined. These data are presented in the table below:

    ______________________________________                                        PERCENT CHLORINE LOSS AT 80° F./80% RELATIVE                           HUMIDITY                                                                      Aluminum Foil Wrapped Box                                                               Unencapsulated sodium                                                                         Encapsulated sodium                                           dichloroisocyanurate                                                                          dichloroisocyanurate                                Time Elapsed                                                                            dihydrate/Rinso dihydrate/Rinso                                     ______________________________________                                        1 month   13.0            0.0                                                 2 months  16.0            0.0                                                 3 months  24.0            0.0                                                 ______________________________________                                    

2. A similar test was conducted at more "normal" conditions namely 95°F./50% Relative Humidity. In this test a common outside wax laminatedbox was used. Comparison of the encapsulate, at 10% level in Rinso, withthe same control is indicated below:

    ______________________________________                                        PERCENT CHLORINE LOSS AT 95° F./50% RELATIVE                           HUMIDITY                                                                      Outside Wax Laminated Box                                                               Unencapsulated sodium                                                                         Encapsulated sodium                                           dichloroisocyanurate                                                                          dichloroisocyanuate                                 Time Elapsed                                                                            dihydrate/Rinso dihydrate/Rinso                                     ______________________________________                                        1 month   20.6            0.0                                                 2 months  24.5            0.0                                                 3 months  29.7            0.1                                                 ______________________________________                                    

EXAMPLE 4

    ______________________________________                                                                Percent                                               ______________________________________                                        sodium dichloroisocyanurate dihydrate                                                                   47.00                                               (a) Emersol 150                   16.50                                                           Coat 1                                                    (b) Witco X-145A                  1.83                                        Emersol 150                       21.67                                       Witco X-145A        Coat 2        1.00                                        (c) Pluronic F-127                12.00                                                                         100.00                                      ______________________________________                                         (a), (b), (c) as defined under Example 1                                 

EXAMPLE 5

    ______________________________________                                                                Percent                                               ______________________________________                                        [(monotrichloro)-tetra-(monopotassium                                                                   51.00                                               dichloro)]Penta isocyanurate                                                  (a) Emersol 150                   16.50                                                           Coat 1                                                    (b) Witco X-145A                  1.83                                        Emersol 150                       16.80                                                           Coat 2                                                    Witco X-145A                      1.87                                        (d) Pluronic F-108                12.00                                                                         100.00                                      ______________________________________                                         (a), (b) as defined under Example 1                                           (d) a block copolymer of 80% polyoxyethylene and 20% polyoxypropylene         having a molecular weight of approximately 16,250                        

EXAMPLE 6

    ______________________________________                                                                Percent                                               ______________________________________                                        potassium dichlorocyanurate                                                                             50.0                                                (a) Emersol 150                   18.0                                                            Coat 1                                                    (b) Witco X-145A                  3.0                                         Emersol 150                       15.0                                        Witco X-145A        Coat 2        1.0                                         (c) Pluronic F-127                13.0                                                                          100.0                                       ______________________________________                                         (a), (b), (c) as defined under Example 1.                                

EXAMPLE 7

    ______________________________________                                                                Percent                                               ______________________________________                                        sodium dichloroisocyanurate dihydrate                                                                   52.0                                                (e) Emersol 153                   21.6                                                            Coat 1                                                    (f) Witco HS                      2.4                                         Emersol 153                       14.0                                        Witco HS            Coat 2        2.0                                         (d) Pluronic F-108                8.0                                                                           100.0                                       ______________________________________                                         (d) as defined under Example 5.                                               (e) 95% stearic acid, 5% palmitic acid                                        (f) a microcrystalline wax containing a blend of alkylated naphthenes,        paraffins and isoparaffins having a melting point of 160-170° F.  

EXAMPLE 8

    ______________________________________                                                                Percent                                               ______________________________________                                        [(monotrichloro)-tetra-(monopotassium                                                                   55.0                                                dichloro)]Penta isocyanurate                                                  (e) Emersol 153                   18.0                                                            Coat 1                                                    (f) Witco HS                      2.0                                         Emersol 153                       9.5                                         Witco HS            Coat 2        0.5                                         (c) Pluronic F-127                15.0                                                                          100.0                                       ______________________________________                                         (c) as defined under Example 1.                                               (e) and (f) as defined under Example 7.                                  

EXAMPLE 9

    ______________________________________                                                                Percent                                               ______________________________________                                        1,3-Dichloro 5,5-Dimethyl Hydantoin                                                                     47.00                                               (a) Emersol 150                   16.50                                                           Coat 1                                                    (b) Witco X-145A                                                              Emersol 150                       1.83                                        Witco X-145A        Coat 2        22.17                                       (d) Pluronic F-108                10.00                                                                         100.00                                      ______________________________________                                         (a) and (b) as defined under Example 1.                                       (d) as defined under Example 5.                                          

EXAMPLE 10

    ______________________________________                                                                Percent                                               ______________________________________                                        1,3-Dichloro 5,5-Dimethyl Hydantoin                                                                     51.0                                                (e) Emersol 153                   18.0                                                            Coat 1                                                    (f) Witco HS                      2.0                                         Emersol 153                       13.5                                        Witco HS            Coat 2        1.5                                         (c) Pluronic F-127                14.0                                                                          100.0                                       ______________________________________                                         (c) as defined under Example 1.                                               (e) and (f) as defined under Example 7.                                  

EXAMPLE 11

    ______________________________________                                                               Percent                                                ______________________________________                                        Sodium Percarbonate              65.33                                        (a) Emersol 150                  22.17                                        (b) Witco X-145A     Coat 1      2.50                                         (d) Pluronic F-108               10.00                                                                         100.00                                       ______________________________________                                         (a) and (b) as defined under Example 1.                                       (d) as defined under Example 5.                                          

EXAMPLE 12

    ______________________________________                                                               Percent                                                ______________________________________                                        Sodium Perborate                 47.00                                        (a) Emersol 150                  16.50                                                             Coat 1                                                   (b) Witco X-145A                 1.83                                         Emersol 150                      22.17                                        Witco X-145A         Coat 2      2.50                                         (d) Pluronic F-108               10.00                                                                         100.00                                       ______________________________________                                         (a) and (b) as defined under Example 1                                        (d) as defined under Example 5.                                          

EXAMPLE 13

    ______________________________________                                                               Percent                                                ______________________________________                                        Sodium Sulfite                   75.0                                         (a) Emersol 150                  16.0                                         (b) Witco X-145A     Coat 1      1.8                                          (d) Pluronic F-108               7.2                                                                           100.0                                        ______________________________________                                         (a) and (b) as defined under Example 1.                                       (d) as defined under Example 5.                                          

EXAMPLE 14

    ______________________________________                                                               Percent                                                ______________________________________                                        Sodium Percarbonate              60.0                                         (g) Emersol 132                  28.0                                                              Coat 1                                                   (h) Carbowax 6000                11.2                                                                          100.0                                        ______________________________________                                         (g) 50% palmitic acid                                                         45.5% stearic acid                                                            2.5% myristic acid                                                            1.5% margaric acid                                                            .5% pentadecanoic                                                             (h) polyethylene glycol of molecular weight about 6000.                  

EXAMPLE 15

    ______________________________________                                                               Percent                                                ______________________________________                                        sodium dichloroisocyanurate                                                                            47.00                                                (a) Emersol 150                  16.50                                                             Coat 1                                                   (b) Witco X-145A                 1.83                                         Emersol 150                      22.17                                        Witco X-145A         Coat 2      2.50                                         (i) Pluronic F-98                10.00                                                                         100.00                                       ______________________________________                                         (a) and (b) as defined under Example 1.                                       (i) a block copolymer of 80% polyoxyethylene 20% polyoxypropylene having      molecular weight of about 13,750                                         

EXAMPLE 16

    ______________________________________                                                                Percent                                               ______________________________________                                        [(monotrichloro)-tetra-(monopotassium                                                                   50.00                                               dichloro)]Penta isocyanurate                                                  (a) Emersol 150                   16.50                                                           Coat 1                                                    (b) Witco X-145A                  1.83                                        (e) Emersol 153                   23.67                                                           Coat 2                                                    (j) Pluronic F-68                 8.00                                                                          100.00                                      ______________________________________                                         (a) and (b) as defined under Example 1                                        (e) as defined under Example 7                                                (j) a block copolymer of 80% polyoxyethylene, 20% polyoxypropylene having     a molecular weight of about 8,750                                        

EXAMPLE 17

    ______________________________________                                                               Percent                                                ______________________________________                                        potassium dichlorocyanurate                                                                            52.00                                                (a) Emersol 150                  16.50                                                             Coat 1                                                   (b) Witco X-145A                 1.83                                         (e) Emersol 153                  17.67                                                             Coat 2                                                   (k) Pluronic F-88                12.00                                                                         100.00                                       ______________________________________                                         (a) and (b) as defined under Example 1                                        (e) as defined under Example 7                                                (k) a block copolymer of 80% polyoxyethylene, 20% polyoxypropylene having     a molecular weight of about 11,200.                                      

It is found that Examples 4 through 10 and 15 through 17 have resultssimilar to Examples 1 through 3. Examples 11 through 14 showingperoxygen bleaches and reducing bleaches are similar in storage andrelease results to Example 3.

This invention has been described with respect to certain preferredembodiments and various modifications thereof will become obvious topersons skilled in the art, and are to be included within the spirit andpurview of this application and the scope of the appended claims.

What is claimed is:
 1. A coating for encapsulating granulated agents,said agents being capable of substantially passing through a U.S. sievesize of about 10 mesh and at least about 80% of said agents beingsubstantially retained on a U.S. sieve size of about 45 mesh,comprising:(a) about 15 to about 25% of the total encapsulate weight ofa first coating on said agents consisting essentially of a majorproportion of a substantially saturated fatty acid being substantiallynon-reactive with said agents and having a melting point range of about85° F. to about 135° F. and a plasticizing amount of a microcrystallinewax having a melting point range of about 125° F. to about 210° F.; and(b) about 30% to about 40% of the total encapsulate weight of a secondcoating on said first coating, said second coating consistingessentially of a major proportion of said fatty acid, a sufficientamount of said microcrystalline wax to plasticize said second coatingand about 5 to about 20% of the total encapsulate weight of apolyoxyethylene-polyoxypropylene copolymer having at least about 65% byweight of polyoxyethylene and having a molecular weight of about 8000 toabout 16,500.
 2. A coating as defined in claim 1 wherein said firstcoating is about 18 to about 20% of the total encapsulate weight andwherein said second coating is about 32% to about 38% of the totalencapsulate weight.
 3. A coating as defined in claim 1 wherein the fattyacid of said first coating is at least one n-alkanoic acid of about 12to about 20 carbon atoms.
 4. A coating as defined in claim 3 whereinsaid fatty acid is a mixture selected from the group consisting of:(a)about 83% stearic acid, about 11% palmitic acid and about 6% ofn-alkanoic acids of about 12 to about 20 carbon atoms other than stearicor palmitic acid, and (b) about 95% stearic acid and about 5% palmiticacid.
 5. A coating as defined in claim 1 wherein said granulated agentsare bleaching agents.
 6. A coating as defined in claim 5 wherein saidbleaching agents are active chlorine containing bleaching agents.
 7. Acoating for encapsulating granulated agents, said agents being capableof substantially passing through a U.S. sieve size of about 10 mesh andat least about 80% of said agents being substantially retained on a U.S.sieve size of about 45 mesh, comprising:(a) about 5% to about 15% of thetotal encapsulate weight of a first coating on said agents, said firstcoating consisting essentially of a major portion of a substantiallysaturated fatty acid being substantially non-reactive with said agentsand having a melting point range of about 85% to about 135° F. and aplasticizing amount of a microcrystalline wax having a melting pointrange of about 125° F. to about 210° F.; (b) about 25% to about 40% ofthe total encapsulate weight of a second coating on said first coatedagents, said second coating consisting essentially of a major proportionof said fatty acid, a sufficient amount of said microcrystalline wax toplasticize said second coating and about 5 to about 20% by weight of thetotal encapsulated weight of a polyoxyethylene-polyoxypropylenecopolymer having at least about 65% by weight of polyoxyethylene andhaving a molecular weight of about 8000 to about 16,500; and (c) about5% to about 15% of the total encapsulate weight of a third coating onsaid second coated agents, said third coating consisting essentially ofa major portion of said fatty acid and a sufficient amount of saidmicrocrystalline wax to plasticize said third coating.
 8. A coating asdefined in claim 7 wherein said first coating is about 8 to about 12% ofthe total encapsulate weight, wherein said second coating is about 30%to about 35% of the total encapsulate weight and wherein said thirdcoating is about 8 to about 12% of the total encapsulate weight.
 9. Acoating as defined in claim 7 wherein the fatty acid of said firstcoating is at least one n-alkanoic acid of about 12 to about 20 carbonatoms.
 10. A coating as defined in claim 9 wherein said fatty acid is amixture selected from the group consisting of:(a) about 83% stearicacid, about 11% palmitic acid, and about 6% of n-alkanoic acids of about12 to about 20 carbon atoms other than stearic or palmitic acid, and (b)about 95% stearic acid and about 5% palmitic acid.
 11. A coating asdefined in claim 7 wherein said granulated agents are bleaching agents.12. A coating as defined in claim 11 wherein said bleaching agents areactive chlorine containing bleaching agents.
 13. A coating forencapsulating granulated agents, said agents being capable ofsubstantially passing through a U.S. sieve size of about 10 mesh and atleast about 80% of said agents being substantially retained on a U.S.sieve size of about 45 mesh, comprising:(a) about 35% to about 55% ofthe total encapsulate weight of a coating on said agents consistingessentially of a major proportion of a fatty acid being substantiallynonreactive with said agents and having a melting point range of about85° F. to about 135° F., a plasticizing amount of a microcrystalline waxhaving a melting point range of about 125° F. to about 210° F.; and (b)about 5% to about 20% by weight of the total encapsulate weight of apolyoxyethylene-polyoxypropylene copolymer having a molecular weight ofabout 8000 to about 16,500.
 14. A coating as defined in claim 13 whereinsaid coating is about 7 to about 14% of the total encapsulate weight.15. A coating as defined in claim 13 wherein said fatty acid is at leastone n-alkanoic acid of about 12 to about 20 carbon atoms.
 16. A coatingas defined in claim 15 wherein said fatty acid is a mixture selectedfrom the group consisting of:(a) about 83% stearic acid, about 11%palmitic acid, and about 6% of n-alkanoic acids of about 12 to about 20carbon atoms other than stearic or palmitic acid, and (b) about 95%stearic acid and about 5% palmitic acid.
 17. A coating as defined inclaim 13 wherein said granulated agents are bleaching agents.